JPS6327080A - Solid state laser and manufacture of the same - Google Patents

Abstract

An optically pumped solid state laser which is constructed of components (1, 3, 4, 6, 7) having attached fittings (9-13) which are structured in such a manner that the components are automatically arranged with respect to one another along an optical path upon joining the fittings together.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optically pumped solid state laser and a method for producing the same.

More particularly, the present invention relates to a laser constructed of components equipped with fixtures that are structured such that when the fixtures are connected, the components are arranged along an optical path.

[Conventional technology and problems to be solved]

In the period since the first working laser was demonstrated in 1960, laser development efforts have resulted in a wide variety of lasers in terms of size, power, output frequency, and method of excitation of the active medium (laser material). Most of these devices can be classified as precision instruments and are typically hand-built by skilled workers. The common features of such devices are that they include a resonator, a pump source (a source of energy that creates or activates the laser material), and means for removing heat.
Apart from solid-state semiconductor laser diodes such as those whose f-base is made of argonium arsenide or gallium alumina arsenide,
Most lasers in use today are based on gas discharge technology and are bulky and inefficient.

Such gas discharge techniques include the use of gas discharges directly, as in the case of carbon dioxide lasers, or indirectly, as in the case of flash lamps used to excite the laser material. There is.

If the optical components of the laser are relatively far apart (approximately 15 to 800 cm for conventional lasers), even small angular misalignments can cause significant losses in laser power. Therefore, the laser cavity is designed to ensure stable alignment of these optical components.

Therefore, the design requires the use of highly rigid materials such as amber, glass, granite, steel, and various ceramics for the structure of the resonator.

Heat produced as an undesirable byproduct of laser operation also imposes constraints on laser cavity design. Fluctuations in temperature caused by such thermal stress induce thermal distortion in the resonator, which in turn causes optical components inside the resonator to become misaligned. Conventional laser designs have therefore addressed this problem for some time by using materials with low coefficients of thermal expansion such as amber, crystals, and various ceramics, as well as by thermally stabilizing the cavity using external cooling means. Ta.

It is well known to optically pump or excite solid state laser materials using flash lamps, light emitting diodes, laser diodes or laser diode arrays. Laser materials commonly used in such solid state lasers are crystalline. Alternatively, it includes glass-like upper materials in which active materials such as trivalent neodymium ions are incorporated. Traditional host materials for neodymium ions are glass and utrium alumina garnet (
(hereinafter referred to as YAG). For example, when using neodymium-doped YAG as the laser material in an optically pumped solid-state laser,
It is typically pumped by absorbing light with a wavelength of about 8] Onm and emits light with a wavelength of 1.064 nm.

U.S. Pat. No. 3,624,545, issued to Ross on November 30, 1971, describes an optically pumped solid state laser consisting of a YAG rod site 9 pumped by at least one semiconductor laser diode. Similarly, U.S. Pat. No. 3,753,145, issued to Czesler on August 14, 1973, describes a method for end-pumping neodymium-doped YAG Robbie using one or more semiconductor light emitting diodes. is disclosed. YA doped with neodymium using a Norms laser diode array
A method for end pumping solid state laser materials such as G is described in U.S. Pat. No. 3,982,201 to Rosenkranz et al. Finally, D.L., Sipes used a closely focused semiconductor laser diode array to convert pumping radiation at wavelengths 8] Onm to wavelengths 1.0 nm by second pumping using neodymium-doped YAG.
It has been reported that it can be converted to output radiation of 0.064 nm with high efficiency. (Applied Physics Communication Vol. 47, No. 2, 1985, pp. 74-75) Materials with nonlinear optical properties are well known and have the ability to serve as harmonic generators. For example, 1976
U.S. Patent No. 3 issued to Bierlen et al.
, 949,323 discloses the use of a material with the formula MTtO(XO4) as a second harmonic generator.

(However, M is at least one of Rb, T base, NH4 and 65, and X is at least one of P or As. However, this is different if NN4 is present. In that case, X is only P. This general formula is particularly useful for nonlinear materials such as potassium titanyl
This includes OPO4. Other known nonlinear optical materials are K)(2PO4, LiNbO2゜KNbO3,
L1 engineering 03. H engineering 03. KB508.4) (including but not limited to 2Q and urea. Soviet Journal of Quantum Electronics Vol. 7, No. 1.

(January 1977, pages 1-13, a discussion of the nonlinear optical properties of a series of different uniaxial crystals was published.

Nonlinear optical materials can be exploited to double the frequency of the output radiation of solid state lasers. For example, potassium titanyl phosphate doubles the frequency of the 1.064 nm output of a neodymium-doped YAG laser to 532 nm.
It has been reported that it can be used to provide light with a wavelength of nm. (R, F', Belt et al., Laser Focus/Electronic Optics, October 1985, 120-12
1 page) U.S. Patent No. 4,526,444 (July 1985)
Fanton et al., August 2nd, 2013) is concerned almost exclusively with finder assemblies made of injection molded plastics. The various optical components of the viewfinder are constructed to snap together within the housing.

In particular, both housings are provided with complementary shaped snap-on connectors which allow quick assembly and automatic positioning of the lens parts relative to each other. However, the finder described in this patent is a passive optical system that does not generate light or heat.

There is no teaching in this patent that it can be used and assembled.

[Means for solving problems]

In accordance with the present invention, a robust, lightweight and compact optically pumped solid state laser is constructed from components with complementary shaped fittings. By "laser component" we mean the optical pump and output coupler and any intermediate active or passive optical elements and auxiliary packages for these elements. In this case, the optical elements include a gain medium and any focusing nonlinear optical elements, but exclude a power source for the optical pump. It will be appreciated, of course, that the output coupler consists of a mirror forming the end of the laser resonator or cavity.

One embodiment of the invention is an optically pumped laser consisting of a solid part, the solid part having a complementary shaped fixture, and when the fixture is connected, the solid part is in the optical path. It has a structure that is arranged along the

Another embodiment of the invention is a method of making an optically pumped solid state laser, which comprises the following process.

ta) attaching to said parts a fixture structured such that, when assembled, the parts of said laser are disposed relative to each other along the optical path within a predetermined tolerance; (1)) placing the parts in working relationship by connecting the fittings together; and [C) gluing the fittings together.

It is an object of the present invention to provide an improved optically pumped solid state laser.

Another object of the invention is to provide a lightweight, optically pumped solid state laser.

Another object of the present invention is to provide an optically pumped solid state laser that has relatively low shock sensitivity.

Another object of the invention is to provide a method by which an optically pumped solid state laser can be easily assembled.

It is a further object of the invention to provide an optically pumped solid state laser that can be assembled from parts fitted with injection molded fixtures.

It is a further object of the present invention to provide an optically pumped solid state laser constructed at least in part of a material having a relatively high coefficient of thermal expansion and a relatively low modulus of elasticity, such as plastic.

It is a further object of the invention to provide a method for mass producing optically pumped solid state lasers.

It is a further object of the present invention to provide a method of using injection molding techniques in producing optically pumped solid state lasers.

〔Example〕

Although the invention can be implemented in many forms, two particular examples are shown in FIGS. 1-4. The present invention is not limited to the following examples.

Apart from the housing shown in FIG. 2, FIGS. 1 and 2 of the drawings illustrate a single generally cylindrical embodiment of the optically pumped laser of the present invention. FIG. 1 is a perspective view of an exploded sectional view of this embodiment, and FIG. 2 is a sectional view thereof.

1 and 2, the light from the optical pumping means consisting of elements 1, 2 is provided with a suitable reflective coating on the surface 5, and the light from said pumping means (1 and 2) The light is focused by a lens 3 onto a laser material 4 that is pumped. The reflective coating on the surface 5 is highly transparent for the light emitted by the pumping means (1 and 2), but reflective for the light emitted by the generation of the laser beam of the laser material. The sex is great. The light emitted by the lasing of the laser material 4 passes through a nonlinear optical element that is highly reflective for the light emitted by the laser material but for the frequency modulated light produced by the nonlinear optical material 6. leads to an output bluff with a suitable reflective coating on the substantially transparent surface 8. The output coupler 7 is shaped so as to serve to collimate the output radiation from the laser passing through it.

The parts of the laser: optical pumping means (1 and 2), lens 3. Laser material 4. Nonlinear optical materials6. and the output coupler 7 are the fixtures 9, 10, 11, 1, respectively.
2.13'g is installed. The complementary shapes of these fixtures cause the laser components to automatically align with each other along the optical path when mounted together. Suitable optical pumping means include, but are not limited to, laser diodes, light emitting diodes 9 and laser diode arrays, together with any auxiliary packages or structures. As used herein, the term "optical pumping means" shall include any heat sink or knockage associated with the laser diode, light emitting diode and laser diode array, but excludes the power supply associated therewith. For example, such devices are typically mounted within a metal housing attached to a heat resistant, thermally conductive heat sink.

The highly compatible optical pump source consists of a gallium aluminum arsenide laser diode 2 having a wavelength of approximately 810 nm and mounted on the heat sink 1. The nature of the heat sink 1 may be passive.

However, the heat sink 1 can also be equipped with a thermoelectric cooler to help keep the laser diode 2 at a constant temperature and ensure optical operation of the laser diode 2. It goes without saying that during operation the optical pumping means will be attached to a suitable power source. The electrical leads from laser diode 2 to the power supply are not shown in FIGS. 1 and 2.

Lens 3 converts the light from laser diode 2 into laser material 4
The function qf is performed by concentrating the light on top. This focusing results in high pumping intensities and associated high photon-to-photon conversion efficiencies in the laser material. Conventional optical means for focusing light may be used in place of the single lens 30. For example, a gradient lens, a ball lens, an aspheric lens or a combination of these lenses can be used. However, it will be appreciated that lens 3 is not essential to the laser of the present invention and it is only desirable to use such a focusing means.

Any conventional laser material 4 may be used as long as it can be optically pumped by the selected optical pumping means. Suitable laser materials include, but are not limited to, materials selected from the group consisting of glassy and crystalline host materials doped with active materials. Suitable active materials include, but are not limited to, chromium, titanium, and rare metal ions. As a special case, neodymium-doped YAG is a suitable laser material for use in combination with optical pumping means to produce a source with a wavelength of 810 nm. When pumped by light at this wavelength, neodymium-doped YAG becomes 1,064n
It can emit light with a wavelength of m.

The laser material 4 is shown in FIGS. 1 and 2 as a rod. However, it will be appreciated that the exact geometry and materials of the part can vary widely. For example, the laser material can have a lens-shaped surface or be rhombohedral if desired. Although not shown in the drawings, embodiments of the invention involve the use of fibers of laser material that are end-pumped by optical pumping means. Very suitable fibers for this purpose include, but are not limited to, glass optical fibers doped with rare earth metal ions such as neosiminium. The length of such fiber can be easily adjusted to absorb substantially all of the source from the optical pumping means.

If a very long fiber is required, it can be coiled, for example on a spool, to minimize the overall length of the laser of the invention.

Laser material 4 has a reflective coating on surface 5 . The nature of this coating is conventional, and it is designed to transmit as much of the pumping radiation incident from the laser diode 2 as possible, while having a high degree of reflectivity for the radiation emitted by the laser material 4 during laser light generation. selected. This coating will also be highly reflective to the second harmonic of the radiation produced by the laser light emission of the laser material 4.
The high reflection element serves to prevent pump-side losses caused by double-frequency radiation produced by the non-linear optical material 6 that is not doubled in frequency and reflected back through the non-linear optical material 6 by the coating on the surface 8. I do.

In the case of the neodymium-doped nine YAG Rondo 4 pumped by light with a wavelength of 8] Onm, the coating on the surface 5 is as described above, which almost transmits the light of 8] Onm and transmits the light with a wavelength of 1.064 nm. has high reflectivity.

This coating is also highly reflective for light with a wavelength of 532 nm. and the second harmonic is above 1.0
It is further desirable that the material has reflectivity to a wavelength of 64 nm. It goes without saying that the wavelength-selective mirror created by coating the surface 5 need not be placed on said surface. If desired, it can be located anywhere between the mirror optical pumping means and the laser material and can be constructed by a coating deposited on a suitable substrate. Further, the mirror may be of any suitable shape. The light emitted by the laser material 4 passes through the nonlinear optical material 6 . By appropriately coordinating the crystal structure of the nonlinear optical material with respect to the incident light created by the laser material 4, the frequency of the incident light can be changed, for example, doubled by passing through the nonlinear optical material 6. Or it can be tripled. As a special example, 1,064n emitted from neodymium-doped YAG laser material 4
Immediately after the light with a wavelength of m passes through the nonlinear optical material 6, it becomes 53
It can be converted into light with a wavelength of 2 nm.

Although the nonlinear optical material 6 is shown as a rod in FIGS. 1 and 2, the geometry of this component can vary widely.

For example, the nonlinear optical material can optionally be rhombohedral in shape with lens-shaped surfaces. Also,
Such a nonlinear optical component can be constructed with heating or cooling means to control the temperature of the nonlinear optical material to optimize its performance as a harmonic generator.

Potassium titanyl phosphate is highly desirable as a nonlinear optical material. However, any of the many known nonlinear optical materials can be used in practicing the present invention. Such known nonlinear optical materials include KHPOLiNbO2, KN
bO3, Li engineering 03. H engineering 03゜2 4' KB, 08・4H20, urea, and formula MT10 (X0
4) (where M is selected from the group consisting of Rb, TI, and X is selected from the group consisting of P and A8), but is not limited thereto. The nonlinear optical material 6 is not an essential laser component and its use merely represents one embodiment of the invention.

Since the nonlinear optical material 6 is not 100% efficient as a second harmonic generator, the light passing through this component 2 from the laser material 4 is usually a mixture of double frequency light and unmodulated light. . In the original case with a wavelength of 1,064 ni, emitted from YAG doped with neodymium as the laser material 4, the light passing through the nonlinear optical material 6 would be a mixture of wavelengths of 1,064 nm and 532 n1lH. . This wavelength mixer is directed towards an output coupler 7 which has a reflective coating on its wavelength selective surface. The nature of this coating is conventional and chosen such that it is nearly transparent to 532 nm light but highly reflective to 1,064 nm light. Therefore, only double frequency light having a wavelength of 532 nm will be emitted through the output coupler.

The wavelength selective mirror created by coating surface 8 need not be of the precise design shown in FIGS. 1 and 2, but may be of conventional type. For example, a wavelength selective mirror can be created by coating the surface 14 of the nonlinear optical material 6.

In this case, the output coupler 7 could be removed or replaced by optical means whose sole purpose is to collimate or correct the output radiation from the laser. However, the concave shape of the mirror created by the coating on surface 8 causes the reflected light, which has not been frequency doubled, to be reflected back onto nonlinear optical material 6, pass through laser material 4, and be focused onto the coating on surface 5. It has the advantage of allowing As mentioned above, this coating of surface 5 is preferably highly reflective for both frequency-doubled light and unmodulated light from the lasing of laser material 4. Therefore,
Frequency-unmodulated light reflected by the coating on surface 8 is partially frequency doubled by passing through the nonlinear optical material 6, and the resulting mixture of wavelengths is reflected from the coating on surface 5 to form the nonlinear optical material. Some of the remaining frequency-unmodulated light passing back through the material 6 is frequency doubled and the frequency doubled light is emitted through the output coupler 7. With the exception of losses that occur as a result of processes such as scattering and absorption, by further repeating this sequence of events all of the original produced by the lasing of the laser material 4 is doubled in frequency and sent to the output coupler 7. As a result, light is emitted through the .

The fixtures 9, 10, 11, 12.13 are configured such that when assembled together, the various parts of the laser are automatically positioned relative to each other along the optical path. Fittings 9.11 are shaped to fit into complementary recesses in fitting 10. Similarly, fittings 11 and 13 are shaped Z to fit into complementary recesses in fitting 12. Preferably, the fixtures are shaped such that the laser components are positioned relative to each other within a predetermined tolerance when the fixtures are connected. If necessary, these tolerances can be made relatively large so that the parts are accurately spaced from each other as a whole, so that optimization of laser performance can empirically adjust the final spacing between the parts. This can be achieved by doing this. For example, FIG. 2 shows fittings 9, 10 that fit tightly together.

However, if required, the fittings 9, 10 can be adjusted until this tight fit positions the diode laser 2 at a generally accurate distance from the lens 3 until optimal laser performance is achieved. 10 can be optimized empirically by slightly moving them relative to each other.

A further preferred embodiment of the invention includes a fixture configured such that when the fixtures are connected, the laser components are placed in working relationship with respect to each other along the optical path within a predetermined tolerance. use.

The fittings 9, 10, 11, 12.13 can be glued together using conventional techniques or combinations thereof, if desired. For example, the fixture can be welded or bonded with one or more adhesives or bonds. Alternatively, the assembled fixture and associated laser components may be enclosed within a housing that co-contains the fixture. For example, metal, plastic or ceramic housings could be used. In fact, a highly preferred embodiment of the invention uses an injection molded plastic housing. A generally tubular housing 15 is shown in FIG. Mounting tool 9゜10, ]1.12
．． 13 can also be glued together by the use of snap-on connection means or other fastening means incorporated within or on the fitting itself. - By way of example, the fittings can be provided with threads so that they are held together by threaded threads.

The fittings 9, 10, 11, 12.13 fit together to form a generally tubular structure around the various laser components. However, it will be understood that this is merely one embodiment of the invention and that the fixture of the invention may take any convenient shape.

For example, the fixture may only enclose the laser component on two sides rather than on all sides as shown in FIGS. 1 and 2. If desired, the fixtures can be designed to form a substantially flat platform, tray or draft when mated together. It should be appreciated that the exact shape of the fixture is often dictated by manufacturing convenience and considerations of the intended use of the assembled laser.

The fixture of the present invention may be constructed from any suitable rigid material, such as metal, ceramic, gas, thermoplastic and thermoset materials. Additionally, the fixture can be made by any conventional technique. For example, metal fittings can be fabricated by cutting or die-casting, and die-cast aluminum fittings are particularly satisfactory. A further preferred embodiment of the invention uses a fitting made of one or more thermoplastic materials. Suitable thermoplastic materials are polyvinyl chloride, nylon, fluorocarbons, linear polyethylene, polyurethane prepolymers, polystyrene, polypropylene, and cellulose as well as acrylics! including but not limited to. Composites of such thermoplastic materials with various fibers and other reinforcing agents can also be used, if desired. Thermoplastic and glass fittings can also be conveniently fabricated by injection molding techniques. For example, the fixture can be attached to the laser component by the simple method of injection molding the fixture around the component. In fact, if a suitable glass or thermoplastic material is chosen, the passive optics of the laser and associated fittings can be injection molded as a single unit. Such passive optics may use any lens, for example lens 3
The assembly 10 and its fixture 10 can be made in one piece from the same glass or thermoplastic material.

If desired, a single fixture can be fabricated with two or more segments assembled around the associated laser components. For example, fixture 10 can be fabricated in two halves from die cast aluminum or injection molded thermoplastic material. These two halves can then be fitted together around the lens 3 and adhered together by any suitable method to provide the lens 3 with the fitting 10 attached thereto.

The optically pumped solid state laser of the present invention can be of almost any size, but is preferably very small. For example, the overall length of the composition fixture for various laser components is preferably less than about 20 cm, more preferably less than about 10 cm, and even more preferably less than about 5 cm. As a result of such relatively small dimensions, plastics have greater suitability for use in constructing fixtures for laser components. Immediately after assembly, these plastic fixtures provide a plastic structure that holds the various laser components in constant relation to each other. At these relatively small dimensions, the plastic's relatively poor surface stiffness and thermal expansion properties become nearly independent.

Figures 1 and 2 show each laser component 1, 2, 3, and 4, respectively.
．． 6.7 Separate fittings 9. IO,]1.12.1
3 shows an embodiment of the present invention that is installed in the third embodiment.

However, it should be understood that a single fixture can have more than one laser component mounted thereto. For example, fittings 10, 11 can be combined to mount lens 3 and laser material 4 on the same fitting. The number of laser components mounted in a given fixture will typically be determined by manufacturing convenience and economic considerations.

3 and 4 show another embodiment of the invention, which also has a substantially cylindrical shape. Third
The figure is a perspective view of an exploded cross section of this embodiment, and FIG. 4 is a cross-sectional view.

Referring to FIGS. 3 and 4, the optical element 20.21
The light from the optical pumping means (2o, 21) is focused by a lens 22 onto a laser material 23 with a suitable reflective coating on the surface 24 and pumped by the source from said pumping means (2o, 21). The reflective coating on the surface 24 is highly transparent to light traps from the pumping means (20, 21), but highly reflective to the light produced by the laser emission of the lasing material 23. The light emitted by the laser material 23 is emitted from the surface 26.
It is directed to an output coupler 25 having a suitable reflective coating 2 on top to collimate the light passing through it.

The reflective coating on surface 26 is selected such that it transmits some, but not all, of the light emitted by the lasing of lasing material 23. For example, the coating on surface 26 may be approximately 9
It can have a reflectance of 5%. Reflective coatings suitable for use on surfaces 24,26 are conventional.

The optical pumping means (20,2]) and the lens 22 are both mounted in one fixture 27, the laser material 23 is mounted in a fixture 28, and the output coupler 25 is mounted in a fixture 29. The fixtures 27°, 28, and 29 have complementary shapes so that the laser components are automatically aligned along the optical path when fitted together! are doing. Fixture 28.2
9 are shaped such that when tightly fitted together, the output coupler 25 is substantially precisely positioned relative to the laser material 23. However, the positioning of the lens 22 relative to the laser material 23 is optimized empirically by slightly moving the fixtures 27, 28 relative to each other to create a gap 31, 32Y. Preferably, the fixture is constructed such that when connected together, the various laser components will be aligned within a predetermined tolerance relative to each other. It is further desirable that these tolerances be small enough so that the laser components are automatically aligned into working relationship when the fixture is connected.

Once assembled, the fixture 27,
28.29 can be glued together. For example, the first
A suitable method has been described in the above description of the embodiment of the invention shown in FIGS.

As a special case, the optical pumping means is a heat sink 2
0 and gallium aluminum arsenide laser diode 21
It can be constructed from a material that emits light with a wavelength of 8 nm. The electrical leads from laser diode 21 to the power supply are not shown in FIGS. 3 and 4. The light from the laser diode 21 is converted into a wavelength 1 by a lens 22.
Neodymium 7-doped YA that emits light at 0.064 nm
Focused onto the G-rod 23, light at this wavelength is emitted from the laser through an output coupler 25 in the form of a parallel beam or a suitably discrete beam.

When compared with the embodiments of FIGS. 1 and 2, the embodiments of FIGS. 3 and 4 differ in the following points.

That is, (a) nonlinear optical material (6 in Figures 1 and 2) is not used.

0) Optical pumping means of Figures 3 and 4 (20°2
]) and the lens 22 are mounted in one fixture 27, while the optical pumping means (1, 2) of FIGS.
and lens 3 are each mounted on separate fixtures 9.10.

(c) The fixtures 27, 28 of FIGS. 3 and 4 are connected together so that the exact distance between the lens 22 and the laser material 23 can be optimized empirically.

[Brief explanation of the drawing]

Fig. 1 is an exploded cross-sectional perspective view of one embodiment of the present invention, Fig. 2 is a sectional view of the embodiment of the invention shown in Fig. 1 closed in a housing, and Fig. 3 is another embodiment of the present invention. FIG. 4 is a sectional view of the embodiment of the present invention shown in FIG. 3;

Claims (1)

[Scope of Claims] 1. It is characterized by being composed of a plurality of solid parts supplementarily having fittings for connecting to each other, and forming a structure in which each solid part is arranged along an optical path when assembled. optically pumped laser. 2. An optically pumped laser according to claim 1, characterized in that, when assembled, said parts are aligned within a predetermined tolerance. 3. An optically pumped laser according to claim 2, characterized in that, when assembled, said parts are arranged in working relationship. 4. The optically pumped laser of claim 2, wherein at least one of the fixtures is attached to two or more components. 5. The optical device according to claim 2, wherein the fixture is made of at least one material selected from the group consisting of metal, ceramic, glass, thermoplastic material, and thermosetting material. laser pumped into. 6. The optically pumped laser of claim 2, wherein said fixture is constructed of at least one thermoplastic material. 7. Optically pumped laser according to claim 6, characterized in that at least one of said parts is attached to a corresponding fixture by injection molding the fixture around it. 8. The above components include (a) optical pumping means; (b)
and a laser material pumped by said optical pumping means. 9. Optically pumped laser according to claim 8, characterized in that said optical pumping means comprises at least one laser diode. 10. Optically pumped laser according to claim 8, characterized in that the laser material is constituted by a single glass optical fiber doped with rare earth metal ions. 11. Optically pumped laser according to claim 8, characterized in that it has as an additional component optical means for focusing the light from the optical pumping means onto the laser material. . 12. Claim 8, characterized in that it comprises as an additional component a nonlinear optical material through which the output radiation from the laser material passes, said nonlinear optical material changing the frequency of the output radiation from the laser material. The optically pumped laser described in . 13. (a) Attach a fixture to the solid part that has a structure such that the solid parts of the laser are arranged along the optical path within a predetermined tolerance when assembled; (b) Mount the fixtures together. (c) adhering the fixtures to each other. 14. The method of claim 13, wherein at least one of the fixtures is attached to two or more parts of the laser. 15. The method of claim 13, wherein the fixtures are bonded together by an injection molded plastic housing. 16. A method according to claim 13, characterized in that the fitting is constructed of at least one thermoplastic material. 17. A method according to claim 16, characterized in that at least one of the solid parts is attached to a corresponding fixture by injection molding the fixture around it. 18. The solid part comprises (a) an optical pumping means; and (b)
) a laser material pumped by said optical pumping means. 19. A method according to claim 18, characterized in that the solid part further comprises optical means for focusing light from the optical pumping means onto the laser material. 20. Claim 18, characterized in that the solid part further comprises a nonlinear optical material through which the output radiation from the laser material passes, the nonlinear optical material changing the frequency of the output radiation from the laser material. The method described in.